Joint Localization of LOS and NLOS Targets With Clutter Mitigation via Multipath Exploitation Radar

The development of nonline-of-sight target detection (NLOS-TD) technology has significantly enhanced the detection capabilities of radar systems, allowing them to monitor regions that are not within direct visual range. However, current NLOS-TD techniques mainly focus on scenarios involving only NLOS targets, without sufficiently addressing the more complex case where both line-of-sight (LOS) and NLOS targets are present. To address the problem, this article proposes a joint localization method that integrates clutter mitigation for both LOS and NLOS targets. Specifically, first, electromagnetic (EM) wave propagation in typical corner scenarios involving both LOS and NLOS targets is examined. Subsequently, the process of background clutter removal and target localization is formulated as an optimization problem, incorporating low-rank, sparsity, and group sparsity constraints. After that, a proximal gradient (PG)-based iterative method is developed, which suppresses clutter while simultaneously producing images of both LOS and NLOS targets. The efficiency of the method is demonstrated through both simulations and experimental results, confirming its ability to accurately localize LOS and NLOS targets.